(NEW YORK) — An American Airlines pilot who was arrested Saturday after authorities say he failed a breathalyzer test on the runway at Detroit’s Metropolitan Airport was charged Monday with operating an aircraft under the influence of alcohol.

The Wayne County Prosecutor’s Office said John Francis Maguire, 50, has been charged with the misdemeanor and said a date for the arraignment has yet to be scheduled.

Maguire was in the cockpit and allegedly under the influence of alcohol around 6:30 a.m. Saturday, moments before his flight was due to leave for Philadelphia, according to the prosecutor’s office.

He failed a field breathalyzer test and was then arrested and given another test, said Michael Conway, director of public affairs at the Detroit Metropolitan Airport. Maguire’s blood alcohol content was not released, but Conway said it was over the limit for a pilot.

Federal Aviation Administration rules state that pilots cannot fly with a blood alcohol content of 0.04 percent or greater.

The airline said Flight 736 was cancelled and customers were put on other flights.

American Airlines previously said in a statement: “This is a serious matter and we are assisting local law enforcement and the Federal Aviation Administration with the investigation. We will handle this matter appropriately as the safety and care of our customers and employees is our highest priority.”